// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/child/indexed_db/webidbcursor_impl.h"

#include <stddef.h>
#include <stdint.h>

#include <memory>

#include "base/macros.h"
#include "base/memory/ptr_util.h"
#include "base/run_loop.h"
#include "base/threading/thread_task_runner_handle.h"
#include "base/values.h"
#include "content/child/indexed_db/indexed_db_key_builders.h"
#include "content/child/indexed_db/mock_webidbcallbacks.h"
#include "content/child/thread_safe_sender.h"
#include "content/common/indexed_db/indexed_db_key.h"
#include "mojo/public/cpp/bindings/associated_binding.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "third_party/WebKit/public/platform/WebData.h"

using blink::WebBlobInfo;
using blink::WebData;
using blink::WebIDBCallbacks;
using blink::WebIDBKey;
using blink::WebIDBKeyTypeNumber;
using blink::WebIDBValue;
using blink::WebVector;
using indexed_db::mojom::Cursor;
using testing::StrictMock;

namespace content {

namespace {

    class MockCursorImpl : public Cursor {
    public:
        explicit MockCursorImpl(indexed_db::mojom::CursorAssociatedRequest request)
            : binding_(this, std::move(request))
        {
            binding_.set_connection_error_handler(
                base::Bind(&MockCursorImpl::CursorDestroyed, base::Unretained(this)));
        }

        void Prefetch(
            int32_t count,
            ::indexed_db::mojom::CallbacksAssociatedPtrInfo callbacks) override
        {
            ++prefetch_calls_;
            last_prefetch_count_ = count;
        }

        void PrefetchReset(
            int32_t used_prefetches,
            int32_t unused_prefetches,
            const std::vector<std::string>& unused_blob_uuids) override
        {
            ++reset_calls_;
            last_used_count_ = used_prefetches;
        }

        void Advance(
            uint32_t count,
            ::indexed_db::mojom::CallbacksAssociatedPtrInfo callbacks) override
        {
            ++advance_calls_;
        }

        void Continue(
            const IndexedDBKey& key,
            const IndexedDBKey& primary_key,
            ::indexed_db::mojom::CallbacksAssociatedPtrInfo callbacks) override
        {
            ++continue_calls_;
        }

        void CursorDestroyed() { destroyed_ = true; }

        int prefetch_calls() { return prefetch_calls_; }
        int last_prefetch_count() { return last_prefetch_count_; }
        int reset_calls() { return reset_calls_; }
        int last_used_count() { return last_used_count_; }
        int advance_calls() { return advance_calls_; }
        int continue_calls() { return continue_calls_; }
        bool destroyed() { return destroyed_; }

    private:
        int prefetch_calls_ = 0;
        int last_prefetch_count_ = 0;
        int reset_calls_ = 0;
        int last_used_count_ = 0;
        int advance_calls_ = 0;
        int continue_calls_ = 0;
        bool destroyed_ = false;

        mojo::AssociatedBinding<Cursor> binding_;
    };

    class MockContinueCallbacks : public StrictMock<MockWebIDBCallbacks> {
    public:
        MockContinueCallbacks(IndexedDBKey* key = 0,
            WebVector<WebBlobInfo>* webBlobInfo = 0)
            : key_(key)
            , web_blob_info_(webBlobInfo)
        {
        }

        void onSuccess(const WebIDBKey& key,
            const WebIDBKey& primaryKey,
            const WebIDBValue& value) override
        {
            if (key_)
                *key_ = IndexedDBKeyBuilder::Build(key);
            if (web_blob_info_)
                *web_blob_info_ = value.webBlobInfo;
        }

    private:
        IndexedDBKey* key_;
        WebVector<WebBlobInfo>* web_blob_info_;
    };

} // namespace

class WebIDBCursorImplTest : public testing::Test {
public:
    WebIDBCursorImplTest()
    {
        null_key_.assignNull();
        indexed_db::mojom::CursorAssociatedPtr ptr;
        mock_cursor_ = base::MakeUnique<MockCursorImpl>(mojo::MakeRequestForTesting(&ptr));
        cursor_ = base::MakeUnique<WebIDBCursorImpl>(
            ptr.PassInterface(), 1, base::ThreadTaskRunnerHandle::Get());
    }

protected:
    base::MessageLoop message_loop_;
    WebIDBKey null_key_;
    std::unique_ptr<WebIDBCursorImpl> cursor_;
    std::unique_ptr<MockCursorImpl> mock_cursor_;

private:
    DISALLOW_COPY_AND_ASSIGN(WebIDBCursorImplTest);
};

TEST_F(WebIDBCursorImplTest, PrefetchTest)
{
    // Call continue() until prefetching should kick in.
    int continue_calls = 0;
    EXPECT_EQ(mock_cursor_->continue_calls(), 0);
    for (int i = 0; i < WebIDBCursorImpl::kPrefetchContinueThreshold; ++i) {
        cursor_->continueFunction(null_key_, new MockContinueCallbacks());
        base::RunLoop().RunUntilIdle();
        EXPECT_EQ(++continue_calls, mock_cursor_->continue_calls());
        EXPECT_EQ(0, mock_cursor_->prefetch_calls());
    }

    // Do enough repetitions to verify that the count grows each time,
    // but not so many that the maximum limit is hit.
    const int kPrefetchRepetitions = 5;

    int expected_key = 0;
    int last_prefetch_count = 0;
    for (int repetitions = 0; repetitions < kPrefetchRepetitions; ++repetitions) {
        // Initiate the prefetch
        cursor_->continueFunction(null_key_, new MockContinueCallbacks());
        base::RunLoop().RunUntilIdle();
        EXPECT_EQ(continue_calls, mock_cursor_->continue_calls());
        EXPECT_EQ(repetitions + 1, mock_cursor_->prefetch_calls());

        // Verify that the requested count has increased since last time.
        int prefetch_count = mock_cursor_->last_prefetch_count();
        EXPECT_GT(prefetch_count, last_prefetch_count);
        last_prefetch_count = prefetch_count;

        // Fill the prefetch cache as requested.
        std::vector<IndexedDBKey> keys;
        std::vector<IndexedDBKey> primary_keys(prefetch_count);
        std::vector<WebIDBValue> values(prefetch_count);
        for (int i = 0; i < prefetch_count; ++i) {
            keys.push_back(IndexedDBKey(expected_key + i, WebIDBKeyTypeNumber));
            values[i].webBlobInfo = WebVector<WebBlobInfo>(static_cast<size_t>(expected_key + i));
        }
        cursor_->SetPrefetchData(keys, primary_keys, values);

        // Note that the real dispatcher would call cursor->CachedContinue()
        // immediately after cursor->SetPrefetchData() to service the request
        // that initiated the prefetch.

        // Verify that the cache is used for subsequent continue() calls.
        for (int i = 0; i < prefetch_count; ++i) {
            IndexedDBKey key;
            WebVector<WebBlobInfo> web_blob_info;
            cursor_->continueFunction(
                null_key_, new MockContinueCallbacks(&key, &web_blob_info));
            base::RunLoop().RunUntilIdle();
            EXPECT_EQ(continue_calls, mock_cursor_->continue_calls());
            EXPECT_EQ(repetitions + 1, mock_cursor_->prefetch_calls());

            EXPECT_EQ(WebIDBKeyTypeNumber, key.type());
            EXPECT_EQ(expected_key, static_cast<int>(web_blob_info.size()));
            EXPECT_EQ(expected_key++, key.number());
        }
    }

    cursor_.reset();
    base::RunLoop().RunUntilIdle();
    EXPECT_TRUE(mock_cursor_->destroyed());
}

TEST_F(WebIDBCursorImplTest, AdvancePrefetchTest)
{
    // Call continue() until prefetching should kick in.
    EXPECT_EQ(0, mock_cursor_->continue_calls());
    for (int i = 0; i < WebIDBCursorImpl::kPrefetchContinueThreshold; ++i) {
        cursor_->continueFunction(null_key_, new MockContinueCallbacks());
    }
    base::RunLoop().RunUntilIdle();
    EXPECT_EQ(0, mock_cursor_->prefetch_calls());

    // Initiate the prefetch
    cursor_->continueFunction(null_key_, new MockContinueCallbacks());

    base::RunLoop().RunUntilIdle();
    EXPECT_EQ(1, mock_cursor_->prefetch_calls());
    EXPECT_EQ(static_cast<int>(WebIDBCursorImpl::kPrefetchContinueThreshold),
        mock_cursor_->continue_calls());
    EXPECT_EQ(0, mock_cursor_->advance_calls());

    const int prefetch_count = mock_cursor_->last_prefetch_count();

    // Fill the prefetch cache as requested.
    int expected_key = 0;
    std::vector<IndexedDBKey> keys;
    std::vector<IndexedDBKey> primary_keys(prefetch_count);
    std::vector<WebIDBValue> values(prefetch_count);
    for (int i = 0; i < prefetch_count; ++i) {
        keys.push_back(IndexedDBKey(expected_key + i, WebIDBKeyTypeNumber));
        values[i].webBlobInfo = WebVector<WebBlobInfo>(static_cast<size_t>(expected_key + i));
    }
    cursor_->SetPrefetchData(keys, primary_keys, values);

    // Note that the real dispatcher would call cursor->CachedContinue()
    // immediately after cursor->SetPrefetchData() to service the request
    // that initiated the prefetch.

    // Need at least this many in the cache for the test steps.
    ASSERT_GE(prefetch_count, 5);

    // IDBCursor.continue()
    IndexedDBKey key;
    cursor_->continueFunction(null_key_, new MockContinueCallbacks(&key));
    base::RunLoop().RunUntilIdle();
    EXPECT_EQ(0, key.number());

    // IDBCursor.advance(1)
    cursor_->advance(1, new MockContinueCallbacks(&key));
    base::RunLoop().RunUntilIdle();
    EXPECT_EQ(1, key.number());

    // IDBCursor.continue()
    cursor_->continueFunction(null_key_, new MockContinueCallbacks(&key));
    base::RunLoop().RunUntilIdle();
    EXPECT_EQ(2, key.number());

    // IDBCursor.advance(2)
    cursor_->advance(2, new MockContinueCallbacks(&key));
    base::RunLoop().RunUntilIdle();
    EXPECT_EQ(4, key.number());

    EXPECT_EQ(0, mock_cursor_->advance_calls());

    // IDBCursor.advance(lots) - beyond the fetched amount
    cursor_->advance(WebIDBCursorImpl::kMaxPrefetchAmount,
        new MockContinueCallbacks(&key));
    base::RunLoop().RunUntilIdle();
    EXPECT_EQ(1, mock_cursor_->advance_calls());
    EXPECT_EQ(1, mock_cursor_->prefetch_calls());
    EXPECT_EQ(static_cast<int>(WebIDBCursorImpl::kPrefetchContinueThreshold),
        mock_cursor_->continue_calls());

    cursor_.reset();
    base::RunLoop().RunUntilIdle();
    EXPECT_TRUE(mock_cursor_->destroyed());
}

TEST_F(WebIDBCursorImplTest, PrefetchReset)
{
    // Call continue() until prefetching should kick in.
    int continue_calls = 0;
    EXPECT_EQ(mock_cursor_->continue_calls(), 0);
    for (int i = 0; i < WebIDBCursorImpl::kPrefetchContinueThreshold; ++i) {
        cursor_->continueFunction(null_key_, new MockContinueCallbacks());
        base::RunLoop().RunUntilIdle();
        EXPECT_EQ(++continue_calls, mock_cursor_->continue_calls());
        EXPECT_EQ(0, mock_cursor_->prefetch_calls());
    }

    // Initiate the prefetch
    cursor_->continueFunction(null_key_, new MockContinueCallbacks());
    base::RunLoop().RunUntilIdle();
    EXPECT_EQ(continue_calls, mock_cursor_->continue_calls());
    EXPECT_EQ(1, mock_cursor_->prefetch_calls());
    EXPECT_EQ(0, mock_cursor_->reset_calls());

    // Now invalidate it
    cursor_->ResetPrefetchCache();

    // No reset should have been sent since nothing has been received yet.
    base::RunLoop().RunUntilIdle();
    EXPECT_EQ(0, mock_cursor_->reset_calls());

    // Fill the prefetch cache as requested.
    int prefetch_count = mock_cursor_->last_prefetch_count();
    std::vector<IndexedDBKey> keys(prefetch_count);
    std::vector<IndexedDBKey> primary_keys(prefetch_count);
    std::vector<WebIDBValue> values(prefetch_count);
    cursor_->SetPrefetchData(keys, primary_keys, values);

    // No reset should have been sent since prefetch data hasn't been used.
    base::RunLoop().RunUntilIdle();
    EXPECT_EQ(0, mock_cursor_->reset_calls());

    // The real dispatcher would call cursor->CachedContinue(), so do that:
    MockContinueCallbacks callbacks;
    cursor_->CachedContinue(&callbacks);

    // Now the cursor should have reset the rest of the cache.
    base::RunLoop().RunUntilIdle();
    EXPECT_EQ(1, mock_cursor_->reset_calls());
    EXPECT_EQ(1, mock_cursor_->last_used_count());

    cursor_.reset();
    base::RunLoop().RunUntilIdle();
    EXPECT_TRUE(mock_cursor_->destroyed());
}

} // namespace content
